This course focuses on the practical application of data.table in handling complex data sets. In the real world, data sets are often distributed across multiple tables, which poses a challenge when using data analysis functions in R that are designed for single tables. Throughout this course, you will gain the skills to effectively combine data sets into single tables using data.table. You will learn various techniques, such as adding columns from one table to another, filtering a table based on observations in another table, and identifying records across multiple tables that meet specific criteria. Additionally, you will acquire the ability to troubleshoot failed join operations and implement best practices for working with complex data sets. By the end of this course, you will have developed the expertise to become a proficient data.table user.